[U-Boot] [PATCH V2 1/4] mmc: fsl_esdhc: introduce vs18_enable for 1.8V fix I/O

[Jagan Teki]

On Tue, May 9, 2017 at 6:19 PM, Peng Fan <peng.fan at nxp.com> wrote:
>
>
>> -----Original Message-----
>> From: Jagan Teki [mailto:jagannadh.teki at gmail.com]
>> Sent: Tuesday, May 09, 2017 7:09 PM
>> To: Peng Fan <peng.fan at nxp.com>
>> Cc: Stefano Babic <sbabic at denx.de>; u-boot at lists.denx.de
>> Subject: Re: [U-Boot] [PATCH V2 1/4] mmc: fsl_esdhc: introduce vs18_enable
>> for 1.8V fix I/O
>>
>> On Mon, May 8, 2017 at 12:32 PM, Peng Fan <peng.fan at nxp.com> wrote:
>> > When using eMMC with 1.8V I/O, the VSELECT bit need to be set in the
>> > USDHC controller when init.
>> >
>> > This patch adds a parameter "vs18_enable" in fsl_esdhc_cfg structure
>> > and priv data, so each controller can have different settings.
>> >
>> > We could not use CONFIG_SYS_FSL_ESDHC_FORCE_VSELECT, it has problem
>> > that it will apply to all USDHC controllers and it only set the 1.8V
>> > at init phase. So if user does not select to the eMMC device, the
>> > voltage on the I/O pins are not correct.
>> >
>> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
>> > Cc: Jaehoon Chung <jh80.chung at samsung.com>
>> > Cc: York Sun <york.sun at nxp.com>
>> > Cc: Stefano Babic <sbabic at denx.de>
>> > ---
>> >
>> > V2: None
>> >
>> >  drivers/mmc/fsl_esdhc.c | 9 +++++++++
>> >  include/fsl_esdhc.h     | 1 +
>> >  2 files changed, 10 insertions(+)
>> >
>> > diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index
>> > f3c6358..bddfe24 100644
>> > --- a/drivers/mmc/fsl_esdhc.c
>> > +++ b/drivers/mmc/fsl_esdhc.c
>> > @@ -92,6 +92,7 @@ struct fsl_esdhc {
>> >   * @dev: pointer for the device
>> >   * @non_removable: 0: removable; 1: non-removable
>> >   * @wp_enable: 1: enable checking wp; 0: no check
>> > + * @vs18_enable: 1: use 1.8V voltage; 0: use 3.3V
>> >   * @cd_gpio: gpio for card detection
>> >   * @wp_gpio: gpio for write protection
>> >   */
>> > @@ -104,6 +105,7 @@ struct fsl_esdhc_priv {
>> >         struct udevice *dev;
>> >         int non_removable;
>> >         int wp_enable;
>> > +       int vs18_enable;
>>
>> I think this can be achieved with adding "no-1-8-v" property.
>
> We need to support non-dts case.

true, try to support dt as well.

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.